This project consists of 48 subprojects, each of which comprises a separate question to be asked of our comprehensive computerized clinical data storage and retrieval systems. We have collected data on more than 3300 kidney transplants performed at the University of Minnesota since 1968; all information is stored in the mainframe computer system. We have developed an extensive microcomputer database. To date over 800 patients have been entered (all patients transplanted since 1987). Multiple details (preoperative risk factors; tissue typing; the transplant admission and surgery; donor information; posttransplant readmissions, rejections, biopsies, infections and other complications; quality of life; rehabilitation) are available. New transplants are entered prospectively; in addition we are adding patients transplanted prior to 1987 into this database. Two types of studies are planned - retrospective and prospective. In some of these subprojects, data collection has been completed and analysis is planned. In others long-term follow-up is required. Our microcomputer computer database will permit us to study transplant risk factors to an extent that has not previously been possible. The computer allows analysis of mini-series of subgroups of patients and/or multivariate analysis of the importance of risk factors. Among the most important of the subprojects are: A. Long-term follow-up of our randomized trial of MALG vs. OKT3; C. Long-term follow-up of kidney and kidney/pancreas transplants in diabetic patients; D. Outcome related to primary disease; F. Late morbidity and mortality; impact of death with function; I. Unrelated donors; O. CMV and rejection; Q. Randomization of OKT3 vs. MALG for treatment of steroid resistant rejection; DD Pretransplant extra-renal disease as a risk factor for posttransplant complications; EE. Rehabilitation.